1. Field of the Invention
The present invention relates to the art of electrical connectors, and more particularly to a land grid array (LGA) connector with a fastening device with a knob thereof. The fastening device with the knob provided with helical structure can be able to press against a tab of a load plate from the connector gradually to a locked position and simplify the structure of the electrical connector assembly and providing a mechanically and electrically connection between a chip module and a printed circuit board (PCB).
2. Description of the Prior Art
Electrical connectors are widely used for electrically connecting a chip module to a printed circuit board (PCB) in personal computer. Conventionally, an LGA electrical connector mainly comprises an insulative housing, a multiplicity of terminals received in the insulative housing, a metal stiffener surrounding the insulative housing, a load plate pivotally attached to one end of the metal stiffener for pressing the chip module and a lever pivotally attached to an opposite end of the metal stiffener for locking the load plate on the metal stiffener. The LGA electrical connector further includes four washers assembled on four corners of the metal stiffener.
The stiffener is substantially rectangular and comprises a base, a front sidewall extending upwardly from the base for securing the load plate, a back sidewall also extending upwardly from the base for connecting the lever, and a pair of lateral sidewalls upwardly extending from the opposed lateral edges of the base and located between the front sidewall and the back sidewall. The stiffener further defines four circular through holes at corners of the base for retaining the four washers.
U.S. Pat. No. 7,247,041 issued to Ma and Chen on Jul. 24, 2007 discloses a relevant prior LGA connector for electrically connecting an IC package and a printed circuit board. The LGA connector includes an insulative housing or body of a generally rectangular shape, a plurality of conductive terminals held within the insulative housing, a stiffener defining an opening for surrounding a periphery edge of the insulative housing, and a retention structure attached to the stiffener for providing a downward force towards the IC package on the insulative housing so as to establish a reliable interconnection between the IC package and the printed circuit board through the LGA connector. In this LGA connector, the retention structure includes a pressing cover and a lever respectively attached to opposite ends of the stiffener.
However, in these prior designs, when the electrical connector assembly is oriented to a closed position, there usually requires the lever to lock the load plate or the pressing cover on the stiffener. So when the electrical connector assembly is assembled on the printed circuit board, the printed circuit board needs to provide a certain space for the lever. Thus it does not well satisfy the miniaturization trend of the electrical connector assembly. In addition, the electrical connector assembly needs a fastening member to fix the lever on the stiffener. Thereby structure of the electrical connector assembly is complicated, and corresponding manufacturing process is complex.
Thus, there is a need to provide an improved electrical connector and fastening device with a knob thereof that overcomes the above-mentioned problems.